1. Field of the Invention
This invention relates to a roof-mounted air conditioning system using a conductive heat exchanger and an evaporative pad heat exchanger to selectively heat or cool an enclosure.
2. Description of the Prior Art
The present invention is concerned with an air conditioning system adapted for installation in conjunction with a heat exchanger and an evaporative cooler for heating and cooling buildings for year round operation in geographical areas having low atmospheric humidity, and in particular to a low pressure, high capacity air blower that selectively draws external atmospheric air through a heating or cooling heat exchanger and then through an evaporative cooler for supplying the building's heating and cooling demands. The air conditioning system for the building accordingly is so regulated that both heated and cooled air is supplied in suitable quantities to achieve the desired heating and cooling despite varying environmental conditions.
Prior art systems for heating and cooling interior spaces by using conductive and evaporative heat exchangers mounted in series or parallel are shown, for example, in U.S. Pat. Nos. 2,110,024, 3,802,493, 3,833,052, 4,284,128, and 4,505,327. The aforementioned U.S. Pat. No. 4,505,327 furthermore shows that the use of a solar heater is known to heat a heat exchange medium in a conductive heat exchanger used in an air conditioning system of the same general type corresponding to the present invention.
While the above patents illustrate that the combined effects of conductive and evaporative heat exchangers are known, they fail to illustrate a system wherein a heating and cooling heat exchange medium is circulated through a series of heat exchangers and stored in a single storage tank.
The prior art, moreover, as exemplified by the above-mentioned patents, also fails to provide a conductive heat exchanger through which is circulated a heat exchange medium that may selectively be heated by a solar heater or cooled by a cooling heat exchanger, such as, for example, a cooling tower.
In accordance with the prior art, roof-top evaporative type heat exchangers, even when combined with conductive heat exchangers, are not generally provided with simple air control systems for enabling circulation of ambient and return air in various proportions through the system, or selective exhaust of return air with supply of external ambient air only into the system.
It has also not been generally recognized in the prior art that a simple, fully integrated heating and air conditioning system can utilize solar heating, conductive and evaporative pad heat exchangers, and a cooling heat exchanger whereby circulated air can be heated, cooled, and humidified with a minimum expenditure of energy.